The attack took place on Friday in Fatehjung, close to the town of Attock in the central province of Punjab, where Aziz was campaigning for a by-election.
Aziz, 55 and currently finance minister, was travelling in his car after a campaign meeting when a human bomber set off an explosion beside his vehicle, a senior government official said.
"It is sad that some lost their lives and some were wounded. I condole with their families and my resolve for the service of Pakistan and the Islamic world has further strengthened," Aziz told state-run Pakistan Television (PTV) after the attack.
"... my resolve for the service of Pakistan and the Islamic world has further strengthened"
Prime Minister-designate, Pakistan
"It was a suicide attack," a local police official said. "It was an individual who exploded."
Tahir Sadiq, the mayor of Attock who was travelling in the same car with Aziz, said their driver was one of the victims.
Mushahid Husayn, secretary-general of the ruling Pakistan Muslim League, said he spoke to Aziz by telephone shortly after the attack.
"He seemed to be quite OK. He was quite calm and composed," Husayn said.
Needs to win
Two attempts were made on
Musharraf's life last year
Aziz, a former senior executive with Citibank, needs to win a seat in the lower house of parliament, the National Assembly, to qualify for the premiership.
Caretaker Prime Minister Chaudhry Shujaat Husayn, who took over the job after Zafar Allah Khan Jamali resigned in June, will step down if Aziz wins a seat in one of two by-elections set for 18 August.
President Pervez Musharraf persuaded Aziz to end a 30-year career with Citibank in New York to become finance minister after he took power in a bloodless military coup in 1999.
Aziz is credited with turning around a beleaguered economy, but many ordinary Pakistanis view him with suspicion because of his long association with the US, and some even call him an agent of America.
The attack on his life follows two assassination attempts on Musharraf last December, which were blamed on dissidents linked to al-Qaida.